Trap integrity framework for the offshore northern Perth Basin
L. Langhi A , Y. Zhang A , C. Nicholson B , N. Rollet B , G. Bernardel B , R. Kempton A , J. Kennard B and P. Schaubs AA CSIRO.
B Geoscience Australia.
The APPEA Journal 52(2) 682-682 https://doi.org/10.1071/AJ11096
Published: 2012
Abstract
The presence of hydrocarbon accumulations and several palaeo-oil columns in Permian reservoirs across the offshore northern Perth Basin attests to a widespread charge system and suggests that trap integrity is a critical exploration risk. The local structural evolution between the Beagle Ridge and the Wittecarra Terrace and the impact of renewed Mid-Jurassic extension on a series of prospects (Cliff Head, Dunsborough, Lilac, and Morangie) is assessed to define a regional trap integrity framework.
The focus is on the potential development of pathways through the Early Triassic Kockatea Shale regional top seal caused by reactivation of trap bounding faults and/or interaction with newly formed overlying structures. A series of 3D geo-mechanical models are constructed to simulate the Mid-Jurassic deformation and to evaluate the first-order factors controlling the partitioning of reactivation stresses/strains and the development of seal bypass.
In parallel, the local fault seal potential is assessed by focusing on the likelihood of the fault surfaces to reactivate and conduct fluid within the Jurassic stress regimes. The stress data are also used to compute the risk of reactivation in terms of the increase in pore fluid pressure required to bring a fault segment to a state of instability. The overall risk of top seal bypass is primarily driven by the reservoir-bounding faults orientation and dip. The distribution of jogs, the interactions between fault tips, the fault density, the location of regional major fault, the fault propagation mechanisms and top seal brittleness also control locally the integrity of the top seal.
Laurent Langhi is a senior research scientist and research team leader with CSIRO Earth Science and Resource Engineering and has 10 years of experience in petroleum geology and exploration geophysics. After earning an MSc and PhD in geology, he worked as a researcher at UWA and as an exploration geologist/geophysicist in the oil and gas industry. In 2006, he joined CSIRO Petroleum, focusing on structural geology, trap integrity prediction, assessment/visualisation of fluids migration, and geomechanical modelling. He also works in the fields of seismic attributes analysis, and quantitative seismic for conventional hydrocarbon and CCS. |
Yanhua Zhang obtained a BSc (geology) from China Central-South University in 1981, an MS (geology) from the Chinese Academy of Sciences in 1984, and a PhD (structural geology) from Monash University in 1992. He has been working for CSIRO Exploration and Mining as a researcher since late 1992, focusing on numerical simulation of rock deformation and fluid flow. |
Chris Nicholson is a research scientist in Geoscience Australia’s Petroleum and Marine Division. His present research is about the geology and petroleum potential of the southwest Australian margin. He participated in Geoscience Australia’s southwest margin marine reconnaissance survey during 2008–09, which collected physical samples and geophysical datasets to help assess the prospectivity of frontier basins in the area. He is now leading a study into the complex structural architecture of the offshore northern Perth Basin. Previously, he undertook research about the petroleum prospectivity of the Mentelle, Vlaming, and Bremer basins, analogue sandbox modelling of oblique extensional systems, and the structural and geochemical controls on gold mineralisation at Kambalda, WA. He graduated from ANU with a BSc (hons) in 2000. |
Nadege Rollet is a research scientist at Geoscience Australia. She obtained an MSc and a PhD in geology and geophysics from the University of Paris–Pierre et Marie Curie, France. Her studies focus on geodynamic reconstructions and structural framework of the Ligurian Sea in the Western Mediterranean and the South and Southeast Australian margins; on detection and characterisation of natural hydrocarbon seepage on the north, northwest, and southwest Australian margins; and, on the impact of fluid flow features and magmatism on petroleum prospectivity in the Capel and Faust frontier basins, offshore eastern Australia. She is working in a project investigating the petroleum prospectivity of the Perth Basin through a trap integrity study in collaboration with CSIRO and a hydrocarbon seepage survey. |
George Bernardel obtained a BSc (geophysics) (hons) from the University of Sydney (1986) and BEng (computer systems) from USQ (2004). He is a geoscientist at Geoscience Australia, with 15 years of experience in seismic acquisition and processing, seismic interpretation, and Law of the Sea technical analyses. He has recently been involved in geological studies of the northern Lord Howe Rise and seismic data acquisition along the western Australian margin. |
Richard Kempton obtained a BSc (geology) (hons) from the University of Melbourne (1992) and a PhD (geology) from UWA (2000). He is a research scientist with the Fluid History Analysis group at CSIRO Earth Science and Resource Engineering in Perth, with 10 years of experience in charge history reconstruction in Australasian basins using fluid inclusions. He has previously worked as an exploration geologist for Queensland Gas Company and gold exploration companies in WA. |
John Kennard obtained a BSc (geology) (hons) from ANU (1974) and a PhD (geology) from Memorial University of Newfoundland, Canada (1989). He is a senior geoscientist at Geoscience Australia with more than 30 years of experience in geological mapping, sedimentary basin analysis, petroleum geology, and natural hydrocarbon seepage studies, including 12 years of petroleum systems analysis of Australia’s North West Shelf (Browse and Bonaparte basins). He is presently project leader of Geoscience Australia’s Southwest Frontiers Project, focusing on petroleum systems analysis of the offshore northern Perth Basin. |
Peter is a research team leader at CSIRO Earth Science and Resource Engineering. |
References
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